The clock is ticking for the Justice Department to turn over any evidence showing Trump Tower was wiretapped during the 2016 presidential race by Monday, following a request from top lawmakers in the House Intelligence Committee.
Congressional aides told NBC News that the committee sent a letter last week to the acting deputy attorney general. A copy of the letter was also sent to FBI Director James Comey, who has reportedly asked the Justice Department to publicly reject President Donald Trump's claim.
Last week, Trump took to Twitter to make the explosive accusation against former President Barack Obama but did not provide any proof. Obama and his former director of national intelligence have denied the allegations.
The committee said it would look into potential surveillance of political parties as part of its broader investigation of Russian election meddling.